linux/net/netlink/genetlink.c
Johannes Berg 134e63756d genetlink: make netns aware
This makes generic netlink network namespace aware. No
generic netlink families except for the controller family
are made namespace aware, they need to be checked one by
one and then set the family->netnsok member to true.

A new function genlmsg_multicast_netns() is introduced to
allow sending a multicast message in a given namespace,
for example when it applies to an object that lives in
that namespace, a new function genlmsg_multicast_allns()
to send a message to all network namespaces (for objects
that do not have an associated netns).

The function genlmsg_multicast() is changed to multicast
the message in just init_net, which is currently correct
for all generic netlink families since they only work in
init_net right now. Some will later want to work in all
net namespaces because they do not care about the netns
at all -- those will have to be converted to use one of
the new functions genlmsg_multicast_allns() or
genlmsg_multicast_netns() whenever they are made netns
aware in some way.

After this patch families can easily decide whether or
not they should be available in all net namespaces. Many
genl families us it for objects not related to networking
and should therefore be available in all namespaces, but
that will have to be done on a per family basis.

Note that this doesn't touch on the checkpoint/restart
problem where network namespaces could be used, genl
families and multicast groups are numbered globally and
I see no easy way of changing that, especially since it
must be possible to multicast to all network namespaces
for those families that do not care about netns.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-12 14:03:27 -07:00

945 lines
21 KiB
C

/*
* NETLINK Generic Netlink Family
*
* Authors: Jamal Hadi Salim
* Thomas Graf <tgraf@suug.ch>
* Johannes Berg <johannes@sipsolutions.net>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/mutex.h>
#include <linux/bitmap.h>
#include <net/sock.h>
#include <net/genetlink.h>
static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
static inline void genl_lock(void)
{
mutex_lock(&genl_mutex);
}
static inline void genl_unlock(void)
{
mutex_unlock(&genl_mutex);
}
#define GENL_FAM_TAB_SIZE 16
#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
static struct list_head family_ht[GENL_FAM_TAB_SIZE];
/*
* Bitmap of multicast groups that are currently in use.
*
* To avoid an allocation at boot of just one unsigned long,
* declare it global instead.
* Bit 0 is marked as already used since group 0 is invalid.
*/
static unsigned long mc_group_start = 0x1;
static unsigned long *mc_groups = &mc_group_start;
static unsigned long mc_groups_longs = 1;
static int genl_ctrl_event(int event, void *data);
static inline unsigned int genl_family_hash(unsigned int id)
{
return id & GENL_FAM_TAB_MASK;
}
static inline struct list_head *genl_family_chain(unsigned int id)
{
return &family_ht[genl_family_hash(id)];
}
static struct genl_family *genl_family_find_byid(unsigned int id)
{
struct genl_family *f;
list_for_each_entry(f, genl_family_chain(id), family_list)
if (f->id == id)
return f;
return NULL;
}
static struct genl_family *genl_family_find_byname(char *name)
{
struct genl_family *f;
int i;
for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
list_for_each_entry(f, genl_family_chain(i), family_list)
if (strcmp(f->name, name) == 0)
return f;
return NULL;
}
static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
{
struct genl_ops *ops;
list_for_each_entry(ops, &family->ops_list, ops_list)
if (ops->cmd == cmd)
return ops;
return NULL;
}
/* Of course we are going to have problems once we hit
* 2^16 alive types, but that can only happen by year 2K
*/
static inline u16 genl_generate_id(void)
{
static u16 id_gen_idx;
int overflowed = 0;
do {
if (id_gen_idx == 0)
id_gen_idx = GENL_MIN_ID;
if (++id_gen_idx > GENL_MAX_ID) {
if (!overflowed) {
overflowed = 1;
id_gen_idx = 0;
continue;
} else
return 0;
}
} while (genl_family_find_byid(id_gen_idx));
return id_gen_idx;
}
static struct genl_multicast_group notify_grp;
/**
* genl_register_mc_group - register a multicast group
*
* Registers the specified multicast group and notifies userspace
* about the new group.
*
* Returns 0 on success or a negative error code.
*
* @family: The generic netlink family the group shall be registered for.
* @grp: The group to register, must have a name.
*/
int genl_register_mc_group(struct genl_family *family,
struct genl_multicast_group *grp)
{
int id;
unsigned long *new_groups;
int err;
BUG_ON(grp->name[0] == '\0');
genl_lock();
/* special-case our own group */
if (grp == &notify_grp)
id = GENL_ID_CTRL;
else
id = find_first_zero_bit(mc_groups,
mc_groups_longs * BITS_PER_LONG);
if (id >= mc_groups_longs * BITS_PER_LONG) {
size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long);
if (mc_groups == &mc_group_start) {
new_groups = kzalloc(nlen, GFP_KERNEL);
if (!new_groups) {
err = -ENOMEM;
goto out;
}
mc_groups = new_groups;
*mc_groups = mc_group_start;
} else {
new_groups = krealloc(mc_groups, nlen, GFP_KERNEL);
if (!new_groups) {
err = -ENOMEM;
goto out;
}
mc_groups = new_groups;
mc_groups[mc_groups_longs] = 0;
}
mc_groups_longs++;
}
if (family->netnsok) {
struct net *net;
rcu_read_lock();
for_each_net_rcu(net) {
err = netlink_change_ngroups(net->genl_sock,
mc_groups_longs * BITS_PER_LONG);
if (err) {
/*
* No need to roll back, can only fail if
* memory allocation fails and then the
* number of _possible_ groups has been
* increased on some sockets which is ok.
*/
rcu_read_unlock();
goto out;
}
}
rcu_read_unlock();
} else {
err = netlink_change_ngroups(init_net.genl_sock,
mc_groups_longs * BITS_PER_LONG);
if (err)
goto out;
}
grp->id = id;
set_bit(id, mc_groups);
list_add_tail(&grp->list, &family->mcast_groups);
grp->family = family;
genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
out:
genl_unlock();
return err;
}
EXPORT_SYMBOL(genl_register_mc_group);
static void __genl_unregister_mc_group(struct genl_family *family,
struct genl_multicast_group *grp)
{
struct net *net;
BUG_ON(grp->family != family);
rcu_read_lock();
for_each_net_rcu(net)
netlink_clear_multicast_users(net->genl_sock, grp->id);
rcu_read_unlock();
clear_bit(grp->id, mc_groups);
list_del(&grp->list);
genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
grp->id = 0;
grp->family = NULL;
}
/**
* genl_unregister_mc_group - unregister a multicast group
*
* Unregisters the specified multicast group and notifies userspace
* about it. All current listeners on the group are removed.
*
* Note: It is not necessary to unregister all multicast groups before
* unregistering the family, unregistering the family will cause
* all assigned multicast groups to be unregistered automatically.
*
* @family: Generic netlink family the group belongs to.
* @grp: The group to unregister, must have been registered successfully
* previously.
*/
void genl_unregister_mc_group(struct genl_family *family,
struct genl_multicast_group *grp)
{
genl_lock();
__genl_unregister_mc_group(family, grp);
genl_unlock();
}
EXPORT_SYMBOL(genl_unregister_mc_group);
static void genl_unregister_mc_groups(struct genl_family *family)
{
struct genl_multicast_group *grp, *tmp;
list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
__genl_unregister_mc_group(family, grp);
}
/**
* genl_register_ops - register generic netlink operations
* @family: generic netlink family
* @ops: operations to be registered
*
* Registers the specified operations and assigns them to the specified
* family. Either a doit or dumpit callback must be specified or the
* operation will fail. Only one operation structure per command
* identifier may be registered.
*
* See include/net/genetlink.h for more documenation on the operations
* structure.
*
* Returns 0 on success or a negative error code.
*/
int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
{
int err = -EINVAL;
if (ops->dumpit == NULL && ops->doit == NULL)
goto errout;
if (genl_get_cmd(ops->cmd, family)) {
err = -EEXIST;
goto errout;
}
if (ops->dumpit)
ops->flags |= GENL_CMD_CAP_DUMP;
if (ops->doit)
ops->flags |= GENL_CMD_CAP_DO;
if (ops->policy)
ops->flags |= GENL_CMD_CAP_HASPOL;
genl_lock();
list_add_tail(&ops->ops_list, &family->ops_list);
genl_unlock();
genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
err = 0;
errout:
return err;
}
/**
* genl_unregister_ops - unregister generic netlink operations
* @family: generic netlink family
* @ops: operations to be unregistered
*
* Unregisters the specified operations and unassigns them from the
* specified family. The operation blocks until the current message
* processing has finished and doesn't start again until the
* unregister process has finished.
*
* Note: It is not necessary to unregister all operations before
* unregistering the family, unregistering the family will cause
* all assigned operations to be unregistered automatically.
*
* Returns 0 on success or a negative error code.
*/
int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
{
struct genl_ops *rc;
genl_lock();
list_for_each_entry(rc, &family->ops_list, ops_list) {
if (rc == ops) {
list_del(&ops->ops_list);
genl_unlock();
genl_ctrl_event(CTRL_CMD_DELOPS, ops);
return 0;
}
}
genl_unlock();
return -ENOENT;
}
/**
* genl_register_family - register a generic netlink family
* @family: generic netlink family
*
* Registers the specified family after validating it first. Only one
* family may be registered with the same family name or identifier.
* The family id may equal GENL_ID_GENERATE causing an unique id to
* be automatically generated and assigned.
*
* Return 0 on success or a negative error code.
*/
int genl_register_family(struct genl_family *family)
{
int err = -EINVAL;
if (family->id && family->id < GENL_MIN_ID)
goto errout;
if (family->id > GENL_MAX_ID)
goto errout;
INIT_LIST_HEAD(&family->ops_list);
INIT_LIST_HEAD(&family->mcast_groups);
genl_lock();
if (genl_family_find_byname(family->name)) {
err = -EEXIST;
goto errout_locked;
}
if (genl_family_find_byid(family->id)) {
err = -EEXIST;
goto errout_locked;
}
if (family->id == GENL_ID_GENERATE) {
u16 newid = genl_generate_id();
if (!newid) {
err = -ENOMEM;
goto errout_locked;
}
family->id = newid;
}
if (family->maxattr) {
family->attrbuf = kmalloc((family->maxattr+1) *
sizeof(struct nlattr *), GFP_KERNEL);
if (family->attrbuf == NULL) {
err = -ENOMEM;
goto errout_locked;
}
} else
family->attrbuf = NULL;
list_add_tail(&family->family_list, genl_family_chain(family->id));
genl_unlock();
genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
return 0;
errout_locked:
genl_unlock();
errout:
return err;
}
/**
* genl_register_family_with_ops - register a generic netlink family
* @family: generic netlink family
* @ops: operations to be registered
* @n_ops: number of elements to register
*
* Registers the specified family and operations from the specified table.
* Only one family may be registered with the same family name or identifier.
*
* The family id may equal GENL_ID_GENERATE causing an unique id to
* be automatically generated and assigned.
*
* Either a doit or dumpit callback must be specified for every registered
* operation or the function will fail. Only one operation structure per
* command identifier may be registered.
*
* See include/net/genetlink.h for more documenation on the operations
* structure.
*
* This is equivalent to calling genl_register_family() followed by
* genl_register_ops() for every operation entry in the table taking
* care to unregister the family on error path.
*
* Return 0 on success or a negative error code.
*/
int genl_register_family_with_ops(struct genl_family *family,
struct genl_ops *ops, size_t n_ops)
{
int err, i;
err = genl_register_family(family);
if (err)
return err;
for (i = 0; i < n_ops; ++i, ++ops) {
err = genl_register_ops(family, ops);
if (err)
goto err_out;
}
return 0;
err_out:
genl_unregister_family(family);
return err;
}
EXPORT_SYMBOL(genl_register_family_with_ops);
/**
* genl_unregister_family - unregister generic netlink family
* @family: generic netlink family
*
* Unregisters the specified family.
*
* Returns 0 on success or a negative error code.
*/
int genl_unregister_family(struct genl_family *family)
{
struct genl_family *rc;
genl_lock();
genl_unregister_mc_groups(family);
list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
if (family->id != rc->id || strcmp(rc->name, family->name))
continue;
list_del(&rc->family_list);
INIT_LIST_HEAD(&family->ops_list);
genl_unlock();
kfree(family->attrbuf);
genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
return 0;
}
genl_unlock();
return -ENOENT;
}
static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct genl_ops *ops;
struct genl_family *family;
struct net *net = sock_net(skb->sk);
struct genl_info info;
struct genlmsghdr *hdr = nlmsg_data(nlh);
int hdrlen, err;
family = genl_family_find_byid(nlh->nlmsg_type);
if (family == NULL)
return -ENOENT;
/* this family doesn't exist in this netns */
if (!family->netnsok && !net_eq(net, &init_net))
return -ENOENT;
hdrlen = GENL_HDRLEN + family->hdrsize;
if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
return -EINVAL;
ops = genl_get_cmd(hdr->cmd, family);
if (ops == NULL)
return -EOPNOTSUPP;
if ((ops->flags & GENL_ADMIN_PERM) &&
security_netlink_recv(skb, CAP_NET_ADMIN))
return -EPERM;
if (nlh->nlmsg_flags & NLM_F_DUMP) {
if (ops->dumpit == NULL)
return -EOPNOTSUPP;
genl_unlock();
err = netlink_dump_start(net->genl_sock, skb, nlh,
ops->dumpit, ops->done);
genl_lock();
return err;
}
if (ops->doit == NULL)
return -EOPNOTSUPP;
if (family->attrbuf) {
err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
ops->policy);
if (err < 0)
return err;
}
info.snd_seq = nlh->nlmsg_seq;
info.snd_pid = NETLINK_CB(skb).pid;
info.nlhdr = nlh;
info.genlhdr = nlmsg_data(nlh);
info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
info.attrs = family->attrbuf;
genl_info_net_set(&info, net);
return ops->doit(skb, &info);
}
static void genl_rcv(struct sk_buff *skb)
{
genl_lock();
netlink_rcv_skb(skb, &genl_rcv_msg);
genl_unlock();
}
/**************************************************************************
* Controller
**************************************************************************/
static struct genl_family genl_ctrl = {
.id = GENL_ID_CTRL,
.name = "nlctrl",
.version = 0x2,
.maxattr = CTRL_ATTR_MAX,
.netnsok = true,
};
static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
u32 flags, struct sk_buff *skb, u8 cmd)
{
void *hdr;
hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
if (hdr == NULL)
return -1;
NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name);
NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id);
NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version);
NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize);
NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr);
if (!list_empty(&family->ops_list)) {
struct nlattr *nla_ops;
struct genl_ops *ops;
int idx = 1;
nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
if (nla_ops == NULL)
goto nla_put_failure;
list_for_each_entry(ops, &family->ops_list, ops_list) {
struct nlattr *nest;
nest = nla_nest_start(skb, idx++);
if (nest == NULL)
goto nla_put_failure;
NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
nla_nest_end(skb, nest);
}
nla_nest_end(skb, nla_ops);
}
if (!list_empty(&family->mcast_groups)) {
struct genl_multicast_group *grp;
struct nlattr *nla_grps;
int idx = 1;
nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
if (nla_grps == NULL)
goto nla_put_failure;
list_for_each_entry(grp, &family->mcast_groups, list) {
struct nlattr *nest;
nest = nla_nest_start(skb, idx++);
if (nest == NULL)
goto nla_put_failure;
NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
grp->name);
nla_nest_end(skb, nest);
}
nla_nest_end(skb, nla_grps);
}
return genlmsg_end(skb, hdr);
nla_put_failure:
genlmsg_cancel(skb, hdr);
return -EMSGSIZE;
}
static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
u32 seq, u32 flags, struct sk_buff *skb,
u8 cmd)
{
void *hdr;
struct nlattr *nla_grps;
struct nlattr *nest;
hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
if (hdr == NULL)
return -1;
NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name);
NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id);
nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
if (nla_grps == NULL)
goto nla_put_failure;
nest = nla_nest_start(skb, 1);
if (nest == NULL)
goto nla_put_failure;
NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
grp->name);
nla_nest_end(skb, nest);
nla_nest_end(skb, nla_grps);
return genlmsg_end(skb, hdr);
nla_put_failure:
genlmsg_cancel(skb, hdr);
return -EMSGSIZE;
}
static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
{
int i, n = 0;
struct genl_family *rt;
struct net *net = sock_net(skb->sk);
int chains_to_skip = cb->args[0];
int fams_to_skip = cb->args[1];
for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
if (i < chains_to_skip)
continue;
n = 0;
list_for_each_entry(rt, genl_family_chain(i), family_list) {
if (!rt->netnsok && !net_eq(net, &init_net))
continue;
if (++n < fams_to_skip)
continue;
if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
skb, CTRL_CMD_NEWFAMILY) < 0)
goto errout;
}
fams_to_skip = 0;
}
errout:
cb->args[0] = i;
cb->args[1] = n;
return skb->len;
}
static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
u32 pid, int seq, u8 cmd)
{
struct sk_buff *skb;
int err;
skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (skb == NULL)
return ERR_PTR(-ENOBUFS);
err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
if (err < 0) {
nlmsg_free(skb);
return ERR_PTR(err);
}
return skb;
}
static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
u32 pid, int seq, u8 cmd)
{
struct sk_buff *skb;
int err;
skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (skb == NULL)
return ERR_PTR(-ENOBUFS);
err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd);
if (err < 0) {
nlmsg_free(skb);
return ERR_PTR(err);
}
return skb;
}
static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
[CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
[CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
.len = GENL_NAMSIZ - 1 },
};
static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
struct genl_family *res = NULL;
int err = -EINVAL;
if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
res = genl_family_find_byid(id);
err = -ENOENT;
}
if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
char *name;
name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
res = genl_family_find_byname(name);
err = -ENOENT;
}
if (res == NULL)
return err;
if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
/* family doesn't exist here */
return -ENOENT;
}
msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
CTRL_CMD_NEWFAMILY);
if (IS_ERR(msg))
return PTR_ERR(msg);
return genlmsg_reply(msg, info);
}
static int genl_ctrl_event(int event, void *data)
{
struct sk_buff *msg;
struct genl_family *family;
struct genl_multicast_group *grp;
/* genl is still initialising */
if (!init_net.genl_sock)
return 0;
switch (event) {
case CTRL_CMD_NEWFAMILY:
case CTRL_CMD_DELFAMILY:
family = data;
msg = ctrl_build_family_msg(family, 0, 0, event);
break;
case CTRL_CMD_NEWMCAST_GRP:
case CTRL_CMD_DELMCAST_GRP:
grp = data;
family = grp->family;
msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
break;
default:
return -EINVAL;
}
if (IS_ERR(msg))
return PTR_ERR(msg);
if (!family->netnsok) {
genlmsg_multicast_netns(&init_net, msg, 0,
GENL_ID_CTRL, GFP_KERNEL);
} else {
rcu_read_lock();
genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
rcu_read_unlock();
}
return 0;
}
static struct genl_ops genl_ctrl_ops = {
.cmd = CTRL_CMD_GETFAMILY,
.doit = ctrl_getfamily,
.dumpit = ctrl_dumpfamily,
.policy = ctrl_policy,
};
static struct genl_multicast_group notify_grp = {
.name = "notify",
};
static int __net_init genl_pernet_init(struct net *net)
{
/* we'll bump the group number right afterwards */
net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0,
genl_rcv, &genl_mutex,
THIS_MODULE);
if (!net->genl_sock && net_eq(net, &init_net))
panic("GENL: Cannot initialize generic netlink\n");
if (!net->genl_sock)
return -ENOMEM;
return 0;
}
static void __net_exit genl_pernet_exit(struct net *net)
{
netlink_kernel_release(net->genl_sock);
net->genl_sock = NULL;
}
static struct pernet_operations genl_pernet_ops = {
.init = genl_pernet_init,
.exit = genl_pernet_exit,
};
static int __init genl_init(void)
{
int i, err;
for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
INIT_LIST_HEAD(&family_ht[i]);
err = genl_register_family(&genl_ctrl);
if (err < 0)
goto problem;
err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
if (err < 0)
goto problem;
netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
err = register_pernet_subsys(&genl_pernet_ops);
if (err)
goto problem;
err = genl_register_mc_group(&genl_ctrl, &notify_grp);
if (err < 0)
goto problem;
return 0;
problem:
panic("GENL: Cannot register controller: %d\n", err);
}
subsys_initcall(genl_init);
EXPORT_SYMBOL(genl_register_ops);
EXPORT_SYMBOL(genl_unregister_ops);
EXPORT_SYMBOL(genl_register_family);
EXPORT_SYMBOL(genl_unregister_family);
static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
gfp_t flags)
{
struct sk_buff *tmp;
struct net *net, *prev = NULL;
int err;
for_each_net_rcu(net) {
if (prev) {
tmp = skb_clone(skb, flags);
if (!tmp) {
err = -ENOMEM;
goto error;
}
err = nlmsg_multicast(prev->genl_sock, tmp,
pid, group, flags);
if (err)
goto error;
}
prev = net;
}
return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
error:
kfree_skb(skb);
return err;
}
int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
gfp_t flags)
{
return genlmsg_mcast(skb, pid, group, flags);
}
EXPORT_SYMBOL(genlmsg_multicast_allns);